Ep. 3: “Platelets and the Immune System” Featuring Dr. Bernardo Franklin
Apr 27, 2021
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Dr. Bernardo Franklin, a Professor at the University of Bonn, discusses the role of blood platelets in innate immunity, systemic inflammation, and cancer. Topics include T cell cross-reactivity in coronaviruses, maternal immune activation, platelets in immune responses, and challenges in academic systems and scientific self-correction.
Platelets have immune functions influencing cytokine production and immune cell activity.
In vitro studies should consider platelet presence to reflect accurate immune cell functionality.
Platelets are critical in driving inflammatory responses and disease pathology, with dual roles in inflammation.
Deep dives
Platelet Interaction with Immune Cells
Platelets, typically associated with blood clotting, are the second most abundant cells in the blood and outnumber immune cells like neutrophils and macrophages in healthy adults. While traditionally overlooked for their immune functions, recent research indicates that platelets can interact with immune cells, influencing their activity and cytokine production. Studying platelets in the context of inflammation and inflammasome activation revealed that platelets play a crucial role in modulating the activity of other immune cells through cell-cell interactions and cytokine regulation.
Relevance of Platelets in In Vitro Studies
In vitro studies often overlook the presence of platelets in immune cell cultures, potentially affecting the relevance and accuracy of the results obtained. Experiments have shown that the inclusion or exclusion of platelets can significantly impact the transcriptional and functional profiles of immune cells such as neutrophils and monocytes. Adding platelets to cell cultures can restore the full functionality of immune cells and accurately reflect the in vivo environment where platelets play a significant role in immune responses.
Platelet Depletion and Functional Impact on Immune Cells
Platelet depletion experiments revealed the critical role of platelets in influencing the transcriptional and functional behavior of immune cells. Removing platelets from cell cultures can lead to altered inflammatory responses and cytokine production in neutrophils and monocytes. The absence of platelets affects the longevity and activity of immune cells, highlighting the importance of considering platelet-immune cell interactions in in vitro studies to accurately represent the physiological conditions.
Platelets' Role in Inflammation
Platelets play a crucial role in driving inflammatory responses, acting as acute phase reactants during inflammatory conditions. Elevated platelet counts are associated with chronic inflammation markers, hinting at their active role in promoting inflammation rather than just being a passive blood marker. Studies have shown the dual relationship between platelets and inflammation, where inflammation can boost platelet production while platelets themselves enhance inflammatory responses. However, in conditions like sepsis, platelets can have a beneficial role by sequestering harmful substances, emphasizing the complex interplay between platelets and inflammation.
Platelets in Disease Pathology and Therapeutics
Evidence suggests that platelets play a significant role in disease pathology, such as malaria and inflammatory diseases like rheumatoid arthritis and Kawasaki disease. Studies have revealed that platelets can access tumor sites, acquiring tumor antigens and serving as 'educated platelets' that can provide accurate tumor information. Additionally, utilizing platelets for targeted immunotherapy delivery has shown promising results in tumor immunology. Despite ongoing research to understand the precise roles of platelets in inflammation and diseases, including their interactions with immune cells, the field still holds many unanswered questions and potential therapeutic avenues.
Dr. Bernardo Franklin is a Professor at the University of Bonn. His lab studies the role of innate immunity in sterile inflammation and in infectious diseases. More recently, their research has focused on blood platelets and their effects on innate immunity, systemic inflammation and cancer.
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